This invention relates generally to fire extinguishing apparatus, and, more particularly, to a fire extinguishing apparatus having heat-activated means for automatically releasing a fire extinguishing agent. In one important embodiment of the present invention, the apparatus comprises a pressurized tank containing fire extinguishing agent, and separate manual and automatic means for releasing the fire extinguishing agent.
Numerous techniques have been suggested for automatically activating fire extinguishing apparatus when the surrounding temperature surpasses a predetermined threshold value. For example, one broad grouping of prior art automatic fire extinguishing apparatus utilizes valves which open to release a fire extinguishing agent in response to temperature sensitive, spring loaded cams or pistons. Another group of prior art automatic fire extinguishing systems employs frangible seals which are designed to be either shattered or pierced by a separate, temperature sensitive mechanism. Finally, more recent contributions to the art utilize heat sensitive electronic sensing circuits which activate separate fire extinguishing apparatus valves. As a result of their complexity, many of these prior art devices are dangerously unreliable. Furthermore, in all of these cases, the equipment is not only complex, it is also unduly expensive and unwieldy.